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Rb25det ping under hard throttle

Jesseraayy

By Jesseraayy,
in Engines & Forced Induction

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Jesseraayy Apprentice

Jesseraayy

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Alright so my r32 with a s2 rb25det started pinging at about half to 3/4 throttle in 3rd a little bit when i turned the boost up to 9psi with a boost t. I installed a adjustable fpr and up the pressure slightly to about 40psi. The pinging stopped but at a drift day i was at yesterday i noticed it doing it under hard acceleration in second gear. The car is stock apart from the basic fmic exhaust boost t and fpr. Any ideas on what could be causing it? Timing was checked a while ago and it was correct. Only started doing it since the boost was set at 9psi

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Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

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factory base pressure for fuel is actually 43.5psi aka 3 bar so you're actually leaning out the car :)

Also if you want to fix your issue, time for an aftermarket ECU or a Nistune. Conveniently I have an Adaptronic 440D Select Plugin for sale if you wish to sort out your tune with an appropriate tuner.

This means you also can ditch your AFM, run any BOV you wish too.

Jesseraayy Apprentice

Jesseraayy

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20 hours ago, Dose Pipe Sutututu said:

factory base pressure for fuel is actually 43.5psi aka 3 bar so you're actually leaning out the car

Also if you want to fix your issue, time for an aftermarket ECU or a Nistune. Conveniently I have an Adaptronic 440D Select Plugin for sale if you wish to sort out your tune with an appropriate tuner.

This means you also can ditch your AFM, run any BOV you wish too.

Oh really? From what i read 43psi was the max you could go. Ill set it to 43.5psi and see how i go. I intend on getting a nistune but gonna pull my engine soon and freshen everything up before i get a ecu. 

Super Drager Mentor

Super Drager

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Yep set it to 45psi with the hose off as stated above. Also imo you shouldn't be upping the boost on an rb25 with a stock ecu, many people do, however they run an assload of ignition timing from factory. If by any chance you are running lean then this can cause pinging very easily.

Hell i only run 10° coming onto boost ramping up to 12° on mine with an ATR45SS on 16psi. Stock R33 runs over 20° in some high load cells, I'd keep it at 7psi till you can afford to tune it

Jesseraayy Apprentice

Jesseraayy

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1 hour ago, Super Drager said:

Yep set it to 45psi with the hose off as stated above. Also imo you shouldn't be upping the boost on an rb25 with a stock ecu, many people do, however they run an assload of ignition timing from factory. If by any chance you are running lean then this can cause pinging very easily.

Hell i only run 10° coming onto boost ramping up to 12° on mine with an ATR45SS on 16psi. Stock R33 runs over 20° in some high load cells, I'd keep it at 7psi till you can afford to tune it

Oh i never new that. Thanks man

GTSBoy Grand Master

GTSBoy

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They might run a lot of timing at stock boost, but by the time you wind the boost up towards 10 psi the ECU starts to access the top right corner of the maps, where there is a shit ton of fuel and a massive retard of the timing.  R&R is built right into the maps.  Well, it certainly is on Neo maps, which I can see in Nistune, so I have no doubt that it was done that way on the vanilla ECU also (which I can't see in Nistune).  And even if it isn't done that way on the vanilla ECUs, it still happens.  So R&R is Nissan's self-protection mechanism to stop people from grenading stock engines.  Crude and effective.  But it can still all go wrong if the fuel pressure is not right (dud reg, or dud pump, etc) because lean will still ping, even with retarded timing.

Basically, it's not good to wind the boost up on them without having a fix for the ECU.  You can only squeeze a little more out of them before the fun police step in.  The worst thing is, you wind the boost up and it feels faster than stock.  So you wind up a bit more and eventually the placebo effect tells you that it's still going faster, but before too long any extra boost just results in massive fuel consumption and no more speed.

Jesseraayy Apprentice

Jesseraayy

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10 hours ago, GTSBoy said:

They might run a lot of timing at stock boost, but by the time you wind the boost up towards 10 psi the ECU starts to access the top right corner of the maps, where there is a shit ton of fuel and a massive retard of the timing.  R&R is built right into the maps.  Well, it certainly is on Neo maps, which I can see in Nistune, so I have no doubt that it was done that way on the vanilla ECU also (which I can't see in Nistune).  And even if it isn't done that way on the vanilla ECUs, it still happens.  So R&R is Nissan's self-protection mechanism to stop people from grenading stock engines.  Crude and effective.  But it can still all go wrong if the fuel pressure is not right (dud reg, or dud pump, etc) because lean will still ping, even with retarded timing.

Basically, it's not good to wind the boost up on them without having a fix for the ECU.  You can only squeeze a little more out of them before the fun police step in.  The worst thing is, you wind the boost up and it feels faster than stock.  So you wind up a bit more and eventually the placebo effect tells you that it's still going faster, but before too long any extra boost just results in massive fuel consumption and no more speed.

Yea i dont plan i winding it anymore i definitely do notice a little difference from 7-9psi though. But in saying that i dont thrash it round everywhere as it is my daily and like you said dont want to wreck my fuel economy. I get 500km out of a tank give or take 50km depending on how its driven. 

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